of atlanta cool and keep these trees from disappearing. the simple solutions that are already making a difference, one coat at a time — how we can protect our bodies from the effects of extreme heat. plus, the people truly in the hot seat — chief heat officers preparing cities for a hotter future. we start with those record—breaking temperatures of 2023. several cities in the us were sweltering, but probably no—one had it quite as bad as people living in phoenix, arizona. now, the state capital saw at least 55 days at or above 110 degrees fahrenheit. as we know, global warming is making heatwaves more frequent and more intense. and of course, extreme heat is also a matter of survival. in the us, it's a bigger killer than hurricanes, tornadoes and floods combined, potentially contributing to as many as 12,000 premature deaths per year in the us. so how can we keep our communities cool? well, it can feel like a huge challenge, but this is just one of the simple but powerful solutions — trees. it's an old idea finding a new urgency, as i found out recently in the city of atlanta. news report: record-breaking heatwave in the east... - many of our cities simply aren't built for the extreme temperatures being fuelled by climate change. but when it comes to urban heat, some solutions really do grow on trees. it might not look like it, but we are just a few minutes outside of the city of atlanta. this is the connolly nature park. these volunteers with the nonprofit trees atlanta are pruning and pulling to help maintain this patch of urban forest, full of old school—climate technology. i can't help but think weather—wise, and weather disaster—wise, we are better off for all of the trees we have. trees are cheap, easy and effective, lowering temperatures by around ten degrees fahrenheit compared to city streets without them. we keep hearing about it, about the temperatures going up and up. it's like, "we have to do something." so this is what we can do. so, if we can increase our canopy cover, that makes everybody a little bit cooler in the long run, really. as climate change makes many cities around the world even hotter, trees are going to play a crucial role, notjust in soaking up excess carbon emissions, but also in providing shade, keeping temperatures down and giving people a place where they can be outside and still stay cool. when people are hot, the places you would see people outside are underneath trees. they cool the environment, but they actually cool you. but these 27 acres of old growth white oak trees nearly disappeared when they were threatened by development. trees atlanta got involved with it about 25, 26 years ago, when it was going to be developed. and the community really wanted to save it. and with a lot of help from community members and some foundations, we ended up saving the forest. and the development went right down the street. atlanta is known as the city in the forest, and in many areas, you can see its trees at work. this is the atlanta beltline. it used to be a railway. now it's several miles of trails, green spaces and trees looping through the city. it's the largest infrastructure project in america right now. so you're doing this connected 22—mile loop that now is a green loop that gives the city a cooling doughnut. but in places where trees are scarce, like downtown, this is the result. atlanta has lost nearly 80,000 trees to development since 2014. and in some areas of the city, you can really feel the difference. dense buildings and a lack of shade trap and reflect heat, making the effect of heatwaves even worse. it's called the urban heat island effect — when materials like concrete absorb the sun's energy and then hold it, cranking up the thermometer way higher than in greener areas. on average, up to 20 degrees fahrenheit hotter. and it often affects poorer, underserved communities. the downtown district of atlanta has the lowest tree canopy cover of any area, just 3%, compared to nearly 50% for the rest of the city. trees atlanta hopes to change that with a plan to plant 8,000 trees in urban and disadvantaged areas. atlanta isn't the only city on a tree—planting spree. the inflation reduction act, the biggest green investment in us history, provides $1.5 billion for tree planting over the next decade, and projects are under way in all 50 states, including new york, minnesota, arizona and california. and experts say the best time to start planting is now. the whole heat issue is one that i think is going to sneak up on people, and all of a sudden, they're going to want those trees and need those trees and it's going to get later and later if we don't start doing something now. just plant some trees, take care of them and you will make a big difference. so, many of the world's cities will need to adapt to rising temperatures. and sometimes that challenge is so vast, you can see it from space. now, these are urban heat maps. and the red areas are the parts of cities giving off more heat, the blues show where it's cooler, and it really does show the dramatic impact as well of green spaces, white road surfaces and water on cities, helping to cool things down in a natural way, making them more resistant to deadly heatwaves. now, this is las vegas, nevada, and you can see the impacts of tarmac, concrete surfaces and parking lots. see that red there? that's where that heat is building up throughout the day, and then slowly being released at night. all that retained energy will make hot nights even more uncomfortable for residents living there. now, with climate change fuelling longer, more intense heatwaves, several cities in the us — phoenix, los angeles and miami — have appointed chief heat officers to help organise a response. i spoke with jane gilbert about how she handles the hot seat as the chief heat officer in miami—dade county. i think that some people might be asking themselves, "look, miami—dade county, home of south beach, "you're accustomed to heat. "why does miami—dade county even need "a chief heat officer?" we had seniors ending up in our emergency rooms because they were waiting at a bus stop too long. so extreme heat is nationwide, the number one weather—related killer, climate—related killer. and it is also the same in miami—dade county. and looking ahead, as climate change is likely to rise temperatures even further, to see more heatwaves longer lasting, what would be one piece of advice you might give to a city that isn't yet on the front lines of climate change? how should they be preparing? education and outreach, emergency protocols, housing retrofits and then urban heat island mitigation. facing some of the extreme heat that we've been seeing, it can be easy, maybe, to get lost in doom and gloom. but as a chief heat officer, what gives you hope looking towards the future? what gives me hope is that a lot of the solutions are things that will make our cities more liveable, improve our quality of life, provide localjobs, generate generate local business opportunities. it's creating that future—ready city that we want to have. we'll have, as a result, more trees, more healthy homes that are more affordable to live in. and we'll bring down our greenhouse gases. all of these and the investments that it will take to get there will provide localjobs and business opportunities. we want to accelerate transit riding, bring down single use cars. that will also improve our quality of life, make pedestrian experience and biking more enjoyable. that's a healthy way to move around. it's a more enjoyable way to move around. so what gives me hope is that by doubling down and accelerating this work within cities, we can create a future city that we want to live in. and it's notjust cities with chief heat officers. there's now the world's first global chief heat officer. you've said before that the way cities are built are deathtraps for people. just help us understand that. what do you mean by that? it's a little dramatic, but basically what i was trying to express is that our cities are really not made for the kind of climate conditions that we are and we will be facing in the future, especially in relation to extreme heat. how can we start redesigning our cities? we have to really detach ourselves from the use of fossil fuels, and we have to do that fast because we're heating up faster than we thought we're heating up as a planet. and of course, some places are heating up faster than other places. like, for example, europe is heating up twice as fast as the average global temperatures. yes, we can redesign our cities so that they can be cooler, much cooler. we have to think about, "how do we use the public space to actually cool cities "instead of heat cities up?" we also have to make sure that we have specific measures to protect the most vulnerable populations in our cities, like the old people and the little kids and the people with pre—existing conditions and the people that have jobs that expose them to extreme heat. what kinds of solutions have you seen that are already working, that are already being rolled out, to try to accomplish some of what you just said in terms ofjust getting those temperatures down? so, awareness raising. one of the measures that we have taken that i think can change awareness is categorisation of heatwaves. so we can... our brain kind of deals with categories better than... it kind of links categories to risk and to danger. so, you know, you can add colours to that, yellows and oranges and reds, and you can also name heatwaves. another thing that i know that is important is labour laws, like people actually making sure that people that are working in particularly risky conditions do not work under specific hours during the day, take breaks, drink water, and they don't have to choose between feeding their families and risking their lives when they're picking garbage or when they are at salt mines or when they're selling things under extraordinary sun and heat. and also, of course, as i said, there's great examples of cities that are transforming themselves from bringing nature— based solutions. so cities are unearthing rivers and are kind of creating urban forests. and this is really, really making our cities more beautiful and more liveable. well, heat isn'tjust about discomfort. it's also a matter of health and preventing deaths. so, we know that extreme heat can kill. but what actually happens to our bodies? 0h! our medical editor, fergus walsh, visited the heat chamber at st mary's university in london. it's been used by sporting greats like andy murray and max verstappen. but even an amateur like me can show how heat affects our physiology. as my core body temperature starts to creep up, blood vessels near the surface of the skin open up, pushing heat to the surface, trying always to keep that core body temperature on an even keel. that can mean a drop in blood pressure as the heart works harder. now, another key way in which my body regulates its core temperature is through sweat. that's why dehydration can quickly become a problem. working out in this heat is not recommended, but staying fit all year round is. people who regularly exercise are regularly experiencing higher body temperatures internally, because you produce a lot of heat when you exercise. so then that leads to better preparation for these heatwaves. the elderly and those with heart and lung conditions are most at risk from extreme heat, but even the young and fit can feel the effects. it's not just about what the thermometer says. there's another element that we have to think about here, and that's, "how does it actually feel to your body?" that's something that's called the heat index, which my colleague nomia iqbal explains. it's a combination of air temperature and relative humidity and considers both meteorology and biology because it measures the weather's effect on the body. why is that important? because while the temperature can read 90 degrees fahrenheit on a thermostat, humidity can make it feel an extra 10 to 15 degrees hotter. so 90 fahrenheit or 32 celsius is actually 105 fahrenheit or a0 celsius. an extreme heat index makes it harderfor us to combat high temperatures. our body's natural cooling mechanism is sweating, but sweating is not as effective when the heat index is high. and it can be deadly, taking the weather from manageable to dangerous, causing heat strokes, cramps and heat exhaustion. according to a recent study, our exposure to dangerous heat index levels is expected to increase by about ten times as much due to the climate crisis. so what can you do to fight it? limit the amount of time you spend outdoors, drink plenty of water, wear light, loose clothing, and always look for shade outdoors. well, there's already some exciting solutions being rolled out in the us and around the globe. and they don't have to be expensive either, like painting roofs with ultra white uv paint. now, this might sound simple, but the results are impressive. scientists in the us have developed a paint that's significantly whiter than the whitest paint currently available. tests carried out by researchers at purdue university in 2021 on their ultra white paint showed that it reflected more than 98% of sunlight. our science correspondent victoria gill found out more about it. cool, heat—reflecting white roofs are already an urban climate solution that's been embraced in cities around the world. in new york, more than 10 million square feet of roofs have been coated with white heat reflecting paint. but these scientists say their ultra white paint could make those roofs even cooler. while the whitest currently available paints reflect between 80 and 90% of sunlight, these researchers say theirs reflects more than 98%. covering a 1,000 square foot roof with this paint, they estimate, would provide more cooling power than a typical central air conditioner. every 1% of reflectance you get will translate to ten watts per metre square less heating from the sun. so, basically, it provides cooling of 18 kilowatts. that's really a big deal. that's more than a typical air conditioner does for a house with that same kind of space. the secret to its formulation also makes it relatively cheap to produce. the scientists use high concentrations of a compound called barium sulphate that's already used to make paper. in recent years, we've seen white paint splashed across the roofs of cities around the world. now, this is new york city, where over 10 million square feet of rooftops have been painted white under a plan called nyc cool roofs, which says that if every roof surface in the city were covered in the reflective paint, it could cool the city by about 3 degrees fahrenheit. and in india, a nonprofit has been helping women paint their homes and build heat resistance. translation: before, we'd burn if you walked barefoot. _ you couldn't stand here without slippers. the charity has helped paint the roofs of 5,000 homes. shakila's neighbours say they're interested, too. her grandson, mohammed, is one happy customer. translation: it used to be | so hot that we could not stay indoors for a stretch of five minutes. but now it's not the case. it's much cooler inside. today, this little boy has drifted off. the mahila housing trust has been working in informal settlements in india for 28 years and has installed 30,000 cool roofs in nine different states. i caught up with their programme manager, bhavna maheriya. first of all, can you just describe the heat that people in your communities, during the warmest part of the year, are dealing with? i mean, what does that feel like? during the summer, in our grassroot communities, they are suffering a lot. actually, their productivity goes very down and that electricity consumption getting very high, and of course it's affecting their income also. who is affected by this heat the most in these communities? of course, women and children, the pregnant women also, the...aged people also. and we also have seen that their houses are very small. in small, like, in ten by ten room, if five or seven members are staying together, then also heat affect a lot because there is no ventilation and maximum people are, like, staying, living together in small room. so that also affect. i also understand that one of the solutions that you are implementing has to do with painting the roofs of some people's homes white. can you tell me about that? so in ahmedabad, recently, we have, like, applied this reflective white paint. there is one slum... in that slum, more than 100 roofs, we have painted. and now from other communities, they are also, like, raising the demand for solar reflective white paint, because the paint is... of course, the result is around four to five degree celsius. the reduction is also there. their electricity consumption is also reduced. and the third thing is this reflective white paint life is three years. so after three years, again, they need to apply. after implementing these solutions, what kind of reaction have you gotten from people in the community? what are they telling you? when we went there and we asked about what kind of benefit you are getting from applying this solar reflective white paint... women, because in gujarat, women are home base workers, so they are doing some either food processing or some textile, like, mala making kind of work or maybe paper making work. stick makers are there, so their work is really... their home is their workplace. so during the daytime, just because of excessive heat, they were not able to work during the daytime and it was affecting their income. so now women are saying that after applying this paint now, between 2.00 to 5.00pm, they can easily work. they can work during the daytime. and of course they are getting more income also, because their electricity consumption has been reduced because they have applied reflective white paint. researchers at the university of chicago have been looking into the impact of cool roofs, not only on temperatures but also on precious resources like water, which is often used in india for cooling. so we've studied these roofs in the context of urban slums in delhi. and, you know, one of the interesting things we found was sort of an engineering kind of one—on—one description of these roofs would be, "you make the roof reflective, "so temperatures come down." what we found also was that people are using a lot of water to cool down their homes and that water is scarce. you don't have sort of piped water in the house, so it comes with tankers. and so what happens is you're competing with kind of drinking water, bathing and so on. and cooling your home is one of those things you can do. and so what we found, some evidence suggesting was when you put on this reflective paint, indoor temperatures only dropped by a very small amount because people start using less water for cooling. so in other words, the adjustment is behavioural. it's that, "i would rather have more water "than have a cooler home, so i'm going to reduce my inputs "and let the roof take on some of that burden." of course, painting the world's roofs white won't solve the climate crisis on its own, but it shows how small and simple solutions could be one of the many tools in our arsenal to help reduce emissions and tackle rising heat without relying on air conditioning. with our cities now facing so many climate challenges, urban experts are finding new, innovative ways of transforming our public spaces. in new york city, the high line transformed these elevated train tracks into a public park in the sky. and the little island project built an urban oasis on the hudson river. here in washington, dc, this is canal park. it used to be a parking lot. now, it's an urban park, bringing nature into the middle of the city. in the last ten years, we've had a much larger expansion of the installation of these projects. and we are seeing the benefits. we're seeing larger amount of tree canopy, shading streets, reducing your heat island effect there. it is a worthy investment, even if it looks like it's expensive or challenging in the front end. green roofs are another option. people put vegetated roofing systems on their homes or commercial buildings, and essentially they cool the building itself off. and it's engineered to absorb storm water, rainwater that comes from the sky. the more intense, the cooler it tends to be because you've got more vegetation. but the different studies have shown a reduction in adjacent like temperatures, up to about three degrees celsius. and there's plenty of solutions that are a bit more hidden, like reclaiming rainwater for use in irrigation and fountains, electric vehicle charging and native heat—resista nt plants. it's all about planning for the climate of the future. as we go into the future, and cities are facing all these different challenges — from one in 100 storms to long heatwaves — how do projects and parks like this fit into that future? yeah, so it's. .. these kinds of parks, it's really important to design parks that are built for long term planning. so a lot of these trees that are selected for the edges are designed to be there for 200 years. the more buy—in you get from your community and the more support... the green domino effect? exactly, yeah. so that's really important. making sure people are comfortable with what you're doing, i think, helps create more resilient projects that are most likely to thrive long term. our concrete jungles still have a long way to go. but with innovations and people like our chief heat officers, there's certainly cause for hope. now, we've seen a small handful of the real life simple solutions that are already here, and we know cities are working to make these changes and give us that hope for the future. i'm carl nasman, and this has been future earth. hello there. the impacts from storm ciaran continue to be felt. on saturday across the uk, it was a day of sunshine and showers or some longer spells of rain for some of us, all driven in by an area of low pressure. but the low pressure has been named as a new storm that's going to be, again, bringing severe weather to europe. western france gusts hitting 85mph, strong enough to blow over trees. so, again, there's going to be some transport disruption and also power cuts very likely here. all the while, 15—metre—high waves, that's as big as the waves could get, battering the coastline of portugal and north—west spain. and in italy, in tuscany, where we've seen severe flooding over recent days, this extra rain certainly isn't going to help things. the flooding could get worse before it gets better. now, over the next few hours for the uk, it's still quite unsettled. we've got rain tending to ease to more showery conditions across parts of northern england, something a bit drier for a time across the west and temperatures around 3—7 celsius as we head into the first part of sunday morning. so it will be a chilly start to the day. i think through sunday morning, there will be further showers coming and going across eastern scotland, eastern england. otherwise, it's a fine and sunny and dry start to the day. however, into the afternoon we'll see showers build particularly across western areas. but with the winds flowing in more from a west—north—westerly direction, that's crucial for those in southern england that have been affected by those really heavy showers and flooding. well, those winds should push the showers offshore at last. so it should be a dry day in the far south. for those celebrating great great uncle guy's night, well, a few more showers coming and going, particularly across western areas, some clear spells and you'll need to wrap it warmly. it will be quite a chilly one. into monday's forecast then, and things looking unsettled this time across the north and west of the uk, with some showers or longer spells of rain here. a few showers elsewhere across england and wales, but moving through fairly promptly, given the brisk westerly winds and temperatures continue to run a little bit below average. now, deeper into the new week, we'll replace the mixture of sunshine and showers with more general outbreaks of rain as we head in towards the middle part of the week. and of course, with the grounds completely saturated following our prolonged spell of wet weather, we'll have to watch carefully to see if we see more flooding issues as this band of rain works through. it does clear through and it will be followed again by a mixture of sunny spells and showery conditions towards the end of the week. bye for now. live from washington, this is bbc news. ismaily air strikes on gaza reports claim an explosion at a refugee camp has killed dozens. america's top diplomat is on a regional push for humanitarian pauses but rejects new calls for an immediate israeli ceasefire. ceasefire now simply will leave hamas in place, able to regroup and repeat what it did on october seven. and with 36 journalists now confirmed dead since the world dominant war began, we look at the toll it is taking on those reporting from the ground. iam helena humphrey, thanks forjoining me. it has now been four weeks which, since the weeks by her mother's killed more than 11100 people in israel. israel is continuing to push further into israel in its ground offensive with 20 israeli soldiers now reported killed since the operation began. its ground offensive is focused on the north of the territory where it is thought that up to 400,000 people remain, despite calls from israel to move south. this was a scene from gaza a few hours ago.